The Core Facility of this proposal is the central epidemiology and biostatistics component of a wide range of research activities at NYU Medical Center related to Traumatic Brain Injury (TBI), including experimental studies of ionic fluxes in animal models, controlled clinical trials of therapeutic interventions in patients, pilot studies of deep brain stimulation in traumatic coma and studies to evaluate the effectiveness of cognitive rehabilitation techniques. The Core will be responsible for 1) The systematic tracking of recovery and resource utilization in survivors of brain injury, i.e., all persons with TBI who enter NYU Medical Center through one of five pathways - Bellevue Hospital/Neurosurgery, Bellevue Rehabilitation, Rusk Institute (RIRM) Inpatient, RIRM Outpatient, NYU Outpatient Head Trauma Program; 2) The design of clinical and basic science research studies aimed directly or indirectly at reducing the neurobehavioral and cognitive deficits which accompany TBI; 3) The collection and analysis of data from the patient tracking system and from specific clinical research studies designed and implemented with Core collaboration; 4) Serving as a resource in biostatistics, epidemiology, research design, analysis, and measurement to new potential investigators within the Medical Center. The Core will provide the resources for research/question hypothesis definition project design and procedures, monitoring adherence to project guidelines/procedures, data collection, instrument selection and development, forms development, data coding, entry, and error checking, data analysis and interpretation, and report writing; 5) Creating an atmosphere which will be conductive to enhancing interaction among a multi- disciplinary group of investigators.